rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8249/1:b..l P8314/1:b..l rcu: (detected by 0, t=10503 jiffies, g=39221, q=853800 ncpus=2) task:syz.0.659 state:R running task stack:26840 pid:8314 tgid:8311 ppid:5860 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline] RIP: 0010:unwind_next_frame+0xddd/0x2550 arch/x86/kernel/unwind_orc.c:614 Code: 60 4c 89 64 24 18 49 8d 5c 24 f8 4d 8b 66 10 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 84 c0 0f 85 2c 12 00 00 <41> 83 3e 00 0f 95 c0 49 39 df 0f 96 c1 20 c1 49 39 dc 0f 97 c0 20 RSP: 0018:ffffc9000601f298 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc9000601faf8 RCX: 1ffff92000c03e6d RDX: ffffffff90ca2578 RSI: 0000000000000002 RDI: ffffffff8c289e80 RBP: 1ffff92000c03e6e R08: 0000000000000001 R09: ffffffff8e95cce0 R10: ffffc9000601f3b8 R11: ffffffff81b105c0 R12: ffffc90006020000 R13: 1ffff92000c03e6f R14: ffffc9000601f368 R15: ffffc90006018000 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 __slab_free+0x274/0x2c0 mm/slub.c:5608 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] kobject_uevent_env+0x28c/0x9e0 lib/kobject_uevent.c:543 device_remove drivers/base/dd.c:619 [inline] __device_release_driver drivers/base/dd.c:1352 [inline] device_release_driver_internal+0x46f/0x870 drivers/base/dd.c:1375 driver_detach+0x1f3/0x2d0 drivers/base/dd.c:1438 bus_remove_driver+0x226/0x320 drivers/base/bus.c:825 usb_gadget_unregister_driver+0x4e/0x70 drivers/usb/gadget/udc/core.c:1752 raw_release+0xd7/0x260 drivers/usb/gadget/legacy/raw_gadget.c:463 __fput+0x44f/0xa60 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x22c0 kernel/exit.c:975 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7ab939c4ab RSP: 002b:00007f7aba2e7f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffff94 RBX: 0000000000000003 RCX: 00007f7ab939c4ab RDX: 00007f7aba2e7fc0 RSI: 0000000040085503 RDI: 0000000000000003 RBP: 00007f7aba2e8fd0 R08: 0000000000000040 R09: 00007f7aba2e7fc8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502 R13: 0000000800000000 R14: 0000000000000012 R15: 00007f7ab9450ede task:syz.0.637 state:R running task stack:20992 pid:8249 tgid:8249 ppid:5860 task_flags:0x400640 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5893 Code: 06 9f 11 00 00 00 00 eb b5 e8 05 a6 16 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 f5 c0 9e 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 1a 96 19 0a cc 48 8d 3d 32 dc 94 RSP: 0018:ffffc9000d1a6788 EFLAGS: 00000286 RAX: f658908a2236de00 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000002 RSI: ffffffff8e24e50c RDI: ffffffff8c289ee0 RBP: ffff888030bbc960 R08: ffffffff821d2019 R09: ffffffff8e95cce0 R10: ffffc9000d1a692c R11: fffff52001a34d2e R12: 0000000000000002 R13: 0000000000000002 R14: ffffffff8e95cce0 R15: ffff888030bbbd80 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] pte_unmap include/linux/pgtable.h:117 [inline] handle_pte_fault mm/memory.c:6405 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x1bae/0x3170 mm/memory.c:6718 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1683/0x2720 mm/gup.c:1428 __get_user_pages_locked mm/gup.c:1692 [inline] get_dump_page+0x1b5/0x410 mm/gup.c:2192 dump_user_range+0x20a/0x12c0 fs/coredump.c:1372 elf_core_dump+0x34c2/0x3ad0 fs/binfmt_elf.c:2109 coredump_write+0x1216/0x1910 fs/coredump.c:1053 do_coredump fs/coredump.c:1132 [inline] vfs_coredump+0x3807/0x4530 fs/coredump.c:1206 get_signal+0x1107/0x1330 kernel/signal.c:3022 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline] irqentry_exit+0x284/0x730 kernel/entry/common.c:162 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f7ab939c821 RSP: 002b:0000000000000030 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f7ab9616090 RCX: 00007f7ab939c819 RDX: 0000000000000000 RSI: 0000000000000030 RDI: 0000000000000600 RBP: 00007f7ab9432c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f7ab9616128 R14: 00007f7ab9616090 R15: 00007f7ab973fa48 rcu: rcu_preempt kthread starved for 1073 jiffies! g39221 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:101 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x4d9/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: f8 01 4c 8b 7c 24 50 48 bd 00 00 00 00 00 fc ff df 4c 8b 6c 24 20 0f 84 86 16 00 00 e9 03 02 00 00 49 89 d5 48 89 d5 48 89 d8 <48> 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4c RSP: 0018:ffffc900000069b8 EFLAGS: 00000287 RAX: ffffffff90555bb4 RBX: ffffffff90555bb4 RCX: ffffffff90555ba4 RDX: ffffffff90555b90 RSI: ffffffff90d69a5a RDI: ffffffff8c289e80 RBP: ffffffff90555ba4 R08: 000000000000000a R09: ffffffff8e95cce0 R10: ffffc90000006ad8 R11: ffffffff81b105c0 R12: ffffffff8230d3ed R13: ffffffff90555ba0 R14: ffffc90000006a88 R15: ffffffff90555ba0 FS: 0000000000000000(0000) GS:ffff888125214000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555578a2da28 CR3: 00000000600e0000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6246 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6373 kfree_skb_reason include/linux/skbuff.h:1322 [inline] __tcf_kfree_skb_list+0x14b/0x300 net/sched/sch_generic.c:59 tcf_kfree_skb_list include/net/sch_generic.h:1184 [inline] __dev_xmit_skb net/core/dev.c:4300 [inline] __dev_queue_xmit+0x21ba/0x3950 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3401 [inline] neigh_hh_output include/net/neighbour.h:540 [inline] neigh_output include/net/neighbour.h:554 [inline] ip_finish_output2+0xc68/0x1070 net/ipv4/ip_output.c:237 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:438 synproxy_send_client_synack+0x8c1/0xe30 net/netfilter/nf_synproxy_core.c:485 nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x467/0x19f0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6209 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6673 __napi_poll+0xae/0x340 net/core/dev.c:7737 napi_poll net/core/dev.c:7800 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7957 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 ieee80211_rx_bss_info net/mac80211/ibss.c:1160 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1569 [inline] ieee80211_ibss_rx_queued_mgmt+0x1ac7/0x2cb0 net/mac80211/ibss.c:1596 ieee80211_iface_process_skb net/mac80211/iface.c:1795 [inline] ieee80211_iface_work+0x845/0x1380 net/mac80211/iface.c:1849 cfg80211_wiphy_work+0x2cf/0x460 net/wireless/core.c:513 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245